In Chapter 8, Diamond lays out the reasons why some animals have been domesticated and others have not. He wants to make it clear that this is not because the people in some regions are not smart enough or motivated enough to domesticate animals. Instead, he says that there are six different characteristics that an animal needs in order to be domesticated. If an animal lacks even one of these characteristics, it cannot be domesticated. Elephants turn out to be lacking in one characteristic. Let us look at the characteristics; animals need to be “right” in the following ways:

Diet. Only herbivores can really be domesticated.

Growth rate. If an animal takes too long to get big enough to be useful to humans, it will not be domesticated.

Problems of captive breeding. If animals will not breed in captivity, they cannot be domesticated.

Disposition. If an animal is too mean, it cannot be domesticated.

Tendency to panic. If an animal is prone to panicking easily, it is too hard to confine and cannot be domesticated.

Social structure. If an animal does not live in herds with hierarchical social structures, it cannot be easily domesticated.

Elephants turn out to fall short in one way. They do not grow up very quickly. On p. 169 in the paperback edition of the book, Diamond says that it takes about 15 years for them to grow to a usable size. This would be a long time to feed an elephant without getting any benefit from it. Therefore, elephants have not been fully domesticated for work.